Dependence of Ag Deposition Methods on the Photocatalytic Activity and Surface State of TiO2 with Twistlike Helix Structure
Dependence of Ag Deposition Methods on the Photocatalytic Activity and Surface State of TiO2 with Twistlike Helix Structure
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DOI：
10.1021/jp8114012
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发表时间：
2009-05-14
影响因子：
3.7
通讯作者：
Fan, Kangnian
中科院分区：
文献类型：
--
作者：
Li, Jingxia;Xu, Jianhua;Fan, Kangnian
合成了含1%银团簇的螺旋状二氧化钛纳米粒子，并进行了光催化应用测试。通过控制四氯化钛的水解得到了特殊的扭曲螺旋结构，同时探索了多种途径沉积存款银纳米粒子。采用浸渍法、化学沉积法和光沉积法制备了Ag/TiO 2样品。考察了介孔螺旋材料的光催化活性和制备方法对样品最终结构的影响，包括比表面积、孔径、银晶粒尺寸、银分布和银表面含量。通过TEM分析研究了Ag/TiO 2纳米催化剂上Ag团簇或纳米颗粒的分散性和粒径。通过XPS分析确定了表面Ag纳米粒子的含量。利用漫反射光谱和光致发光光谱分析了其对可见光的吸收能力和光生电子、空穴等活性中心的数量。实验结果表明，化学沉积法是制备高分散纳米Ag/TiO 2催化剂的有效方法。化学沉积法制备的Ag/TiO 2样品光催化活性最好，其光催化活性上级于P25和纯TiO 2样品。A-MO光催化剂的上级活性在于其良好的分散性和合适的Ag纳米粒子表面含量，这将有效地降低光生电子和空穴的复合速率，从而提高催化剂的光氧化效率。
The 1% silver clusters containing twistlike helix titania nanoparticles have been synthesized and tested in photocatalytic applications. The special twistlike helix structures were obtained by controlling the hydrolysis of titanium tetrachloride, while variety of routes were investigated to deposit the silver nanoparticles. where impregnation, chemical deposition, and photodeposition methods are adopted to fabricate the Ag/TiO2 samples. The influence of the photocatalytic activity of the mesoporous helix materials and the preparation methods oil the final structure of the samples was investigated, including the Surface area, pore size, silver crystallite size, silver distribution, and silver surface content. The dispersion and particle size of Ag Clusters or nanoparticles on Ag/TiO2 nanocatalysts were investigated by TEM analysis. The surface Ag nanoparticles contents were determined by XPS results. Diffuse reflectance and photoluminescence analysis were used to investigate the visible light adsorption ability and the active sites amount including photoinduced electrons and holes. The experimental results show that the chemical deposition method is all efficient method to synthesize Ag/TiO2 catalysts with highly dispersed nanoparticles of metallic Ag. The Ag/TiO2 sample prepared through the chemical deposition method shows the best photocatalytic activity, and its photocatalytic activity is Superior to that of P25 and pure TiO2 sample. The Superior activity of A-MO, photocatalysts call be rationalized in terms of well dispersion and Suitable surface content of Ag nanoparticles that will effectively decrease the recombination rate of photoinduced electrons and holes and then increase the photooxidation efficiency of the catalysts.